[BEAM-8513] RabbitMqIO: Allow reads from exchange-bound queue without declaring the exchange

• Type: Improvement
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 2.18.0
• Component/s: io-java-rabbitmq
• Environment: testing with DirectRunner
• Assignee: Jean-Baptiste Onofré
• Reporter: Nick Aldwin
• Created: 29/Oct/19 18:41
• Updated: 01/Nov/19 18:57
• Resolved: 01/Nov/19 15:48

Description

The RabbitMqIO always declares an exchange if it is configured to read from it.  This is problematic with pre-existing exchanges (a relatively common pattern), as there's no provided configuration for the exchange beyond exchange type.  (We stumbled on this because RabbitMqIO always declares a non-durable exchange, which fails if the exchange already exists as a durable exchange)

 

A solution to this would be to allow RabbitMqIO to read from an exchange without declaring it.  This pattern is already available for queues via the `queueDeclare` flag.  I propose an `exchangeDeclare` flag which preserves existing behavior except for skipping the call to `exchangeDeclare` before binding the queue to the exchange.

 

Issue Links

• links to: GitHub Pull Request #9937